/*
 *	sha256.c
 *	Release $Name: MATRIXSSL-3-6-1-OPEN $
 *
 *	SHA256 hash implementation
 */
/*
 *	Copyright (c) 2013-2014 INSIDE Secure Corporation
 *	Copyright (c) PeerSec Networks, 2002-2011
 *	All Rights Reserved
 *
 *	The latest version of this code is available at http://www.matrixssl.org
 *
 *	This software is open source; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	This General Public License does NOT permit incorporating this software 
 *	into proprietary programs.  If you are unable to comply with the GPL, a 
 *	commercial license for this software may be purchased from INSIDE at
 *	http://www.insidesecure.com/eng/Company/Locations
 *	
 *	This program is distributed in WITHOUT ANY WARRANTY; without even the 
 *	implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. 
 *	See the GNU General Public License for more details.
 *	
 *	You should have received a copy of the GNU General Public License
 *	along with this program; if not, write to the Free Software
 *	Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *	http://www.gnu.org/copyleft/gpl.html
 */
/******************************************************************************/

#include "../cryptoApi.h"

#ifdef USE_SHA256
/******************************************************************************/

#ifndef PS_SHA256_IMPROVE_PERF_INCREASE_CODESIZE
/*
	The K array
 */

static const uint32 K[64] = {
	0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
	0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
	0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
	0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
	0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
	0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
	0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
	0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
	0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
	0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
	0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
	0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
	0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
};
#endif /* PS_SHA256_IMPROVE_PERF_INCREASE_CODESIZE */

/*
	Various logical functions
 */
#define Ch(x,y,z)			(z ^ (x & (y ^ z)))
#define Maj(x,y,z)			(((x | y) & z) | (x & y)) 
#define S(x, n)				ROR((x),(n))
#define R(x, n)				(((x)&0xFFFFFFFFUL)>>(n))
#define Sigma0(x)			(S(x, 2) ^ S(x, 13) ^ S(x, 22))
#define Sigma1(x)			(S(x, 6) ^ S(x, 11) ^ S(x, 25))
#define Gamma0(x)			(S(x, 7) ^ S(x, 18) ^ R(x, 3))
#define Gamma1(x)			(S(x, 17) ^ S(x, 19) ^ R(x, 10))


/*
	compress 512-bits
 */
#ifdef USE_BURN_STACK 
static void _sha256_compress(psDigestContext_t * md, unsigned char *buf)
#else
void sha256_compress(psDigestContext_t * md, unsigned char *buf)
#endif /* CLEAN_STACK */
{

	uint32 S[8], W[64], t0, t1;
#ifndef PS_SHA256_IMPROVE_PERF_INCREASE_CODESIZE
	uint32 t;
#endif /* PS_SHA256_IMPROVE_PERF_INCREASE_CODESIZE */
	int32 i;

/*
	copy state into S
 */
	for (i = 0; i < 8; i++) {
		S[i] = md->sha256.state[i];
	}

/*
	copy the state into 512-bits into W[0..15]
 */
	for (i = 0; i < 16; i++) {
		LOAD32H(W[i], buf + (4*i));
	}

/*
	fill W[16..63]
 */
	for (i = 16; i < 64; i++) {
		W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) + W[i - 16];
	}

/*
	Compress
 */
#ifndef PS_SHA256_IMPROVE_PERF_INCREASE_CODESIZE
#define RND(a,b,c,d,e,f,g,h,i)							\
	t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i];	\
	t1 = Sigma0(a) + Maj(a, b, c);						\
	d += t0;											\
	h  = t0 + t1;

	for (i = 0; i < 64; ++i) {
		RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],i);
		t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4]; 
		S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
	}
#else /* PS_SHA256_IMPROVE_PERF_INCREASE_CODESIZE */
#define RND(a,b,c,d,e,f,g,h,i,ki)						\
	t0 = h + Sigma1(e) + Ch(e, f, g) + ki + W[i];		\
	t1 = Sigma0(a) + Maj(a, b, c);						\
	d += t0;											\
	h  = t0 + t1;

	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],0,0x428a2f98);
	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],1,0x71374491);
	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],2,0xb5c0fbcf);
	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],3,0xe9b5dba5);
	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],4,0x3956c25b);
	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],5,0x59f111f1);
	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],6,0x923f82a4);
	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],7,0xab1c5ed5);
	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],8,0xd807aa98);
	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],9,0x12835b01);
	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],10,0x243185be);
	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],11,0x550c7dc3);
	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],12,0x72be5d74);
	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],13,0x80deb1fe);
	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],14,0x9bdc06a7);
	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],15,0xc19bf174);
	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],16,0xe49b69c1);
	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],17,0xefbe4786);
	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],18,0x0fc19dc6);
	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],19,0x240ca1cc);
	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],20,0x2de92c6f);
	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],21,0x4a7484aa);
	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],22,0x5cb0a9dc);
	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],23,0x76f988da);
	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],24,0x983e5152);
	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],25,0xa831c66d);
	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],26,0xb00327c8);
	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],27,0xbf597fc7);
	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],28,0xc6e00bf3);
	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],29,0xd5a79147);
	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],30,0x06ca6351);
	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],31,0x14292967);
	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],32,0x27b70a85);
	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],33,0x2e1b2138);
	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],34,0x4d2c6dfc);
	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],35,0x53380d13);
	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],36,0x650a7354);
	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],37,0x766a0abb);
	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],38,0x81c2c92e);
	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],39,0x92722c85);
	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],40,0xa2bfe8a1);
	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],41,0xa81a664b);
	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],42,0xc24b8b70);
	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],43,0xc76c51a3);
	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],44,0xd192e819);
	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],45,0xd6990624);
	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],46,0xf40e3585);
	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],47,0x106aa070);
	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],48,0x19a4c116);
	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],49,0x1e376c08);
	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],50,0x2748774c);
	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],51,0x34b0bcb5);
	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],52,0x391c0cb3);
	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],53,0x4ed8aa4a);
	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],54,0x5b9cca4f);
	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],55,0x682e6ff3);
	RND(S[0],S[1],S[2],S[3],S[4],S[5],S[6],S[7],56,0x748f82ee);
	RND(S[7],S[0],S[1],S[2],S[3],S[4],S[5],S[6],57,0x78a5636f);
	RND(S[6],S[7],S[0],S[1],S[2],S[3],S[4],S[5],58,0x84c87814);
	RND(S[5],S[6],S[7],S[0],S[1],S[2],S[3],S[4],59,0x8cc70208);
	RND(S[4],S[5],S[6],S[7],S[0],S[1],S[2],S[3],60,0x90befffa);
	RND(S[3],S[4],S[5],S[6],S[7],S[0],S[1],S[2],61,0xa4506ceb);
	RND(S[2],S[3],S[4],S[5],S[6],S[7],S[0],S[1],62,0xbef9a3f7);
	RND(S[1],S[2],S[3],S[4],S[5],S[6],S[7],S[0],63,0xc67178f2);

#undef RND

#endif /* PS_SHA256_IMPROVE_PERF_INCREASE_CODESIZE */

/*
	feedback
 */
	for (i = 0; i < 8; i++) {
		md->sha256.state[i] = md->sha256.state[i] + S[i];
	}

}

#ifdef USE_BURN_STACK 
void sha256_compress(psDigestContext_t *md, unsigned char *buf)
{
	_sha256_compress(md, buf);
	psBurnStack(sizeof(uint32) * 74);
}
#endif /* USE_BURN_STACK */

/*
	init the sha256 state
 */
void psSha256Init(psDigestContext_t *md)
{
	psAssert(md != NULL);

	md->sha256.curlen = 0;
	md->sha256.state[0] = 0x6A09E667UL;
	md->sha256.state[1] = 0xBB67AE85UL;
	md->sha256.state[2] = 0x3C6EF372UL;
	md->sha256.state[3] = 0xA54FF53AUL;
	md->sha256.state[4] = 0x510E527FUL;
	md->sha256.state[5] = 0x9B05688CUL;
	md->sha256.state[6] = 0x1F83D9ABUL;
	md->sha256.state[7] = 0x5BE0CD19UL;
#ifdef HAVE_NATIVE_INT64
	md->sha256.length = 0;
#else
	md->sha256.lengthHi = 0;
	md->sha256.lengthLo = 0;
#endif /* HAVE_NATIVE_INT64 */	
}

void psSha256Update(psDigestContext_t *md, const unsigned char *buf, uint32 len)
{
	uint32 n;

	psAssert(md != NULL);
	psAssert(buf != NULL);

	while (len > 0) {
		if (md->sha256.curlen == 0 && len >= 64) {
			sha256_compress(md, (unsigned char *)buf);
#ifdef HAVE_NATIVE_INT64
			md->sha256.length += 512;
#else
			n = (md->sha256.lengthLo + 512) & 0xFFFFFFFFL;
			if (n < md->sha256.lengthLo) {
				md->sha256.lengthHi++;
			}
			md->sha256.lengthLo = n;
#endif /* HAVE_NATIVE_INT64 */
			buf		+= 64;
			len		-= 64;
		} else {
			n = min(len, (64 - md->sha256.curlen));
			memcpy(md->sha256.buf + md->sha256.curlen, buf, (size_t)n);
			md->sha256.curlen	+= n;
			buf					+= n;
			len					-= n;

			if (md->sha256.curlen == 64) {
				sha256_compress (md, md->sha256.buf);
#ifdef HAVE_NATIVE_INT64
				md->sha256.length += 512;
#else
				n = (md->sha256.lengthLo + 512) & 0xFFFFFFFFL;
				if (n < md->sha256.lengthLo) {
					md->sha256.lengthHi++;
				}
				md->sha256.lengthLo = n;
#endif /* HAVE_NATIVE_INT64 */			
				md->sha256.curlen	= 0;
			}
		}
	}
	return;
}

int32 psSha256Final(psDigestContext_t * md, unsigned char *hash)
{
	int32 i;
#ifndef HAVE_NATIVE_INT64
	uint32	n;
#endif

	psAssert(md != NULL);
	psAssert(hash != NULL);

	if (md->sha256.curlen >= sizeof(md->sha256.buf)) {
		psTraceCrypto("psSha256Final error\n");
		return PS_ARG_FAIL;
	}

/*
	increase the length of the message
 */
#ifdef HAVE_NATIVE_INT64
	md->sha256.length += md->sha256.curlen << 3;
#else
	n = (md->sha256.lengthLo + (md->sha256.curlen << 3)) & 0xFFFFFFFFL;
	if (n < md->sha256.lengthLo) {
		md->sha256.lengthHi++;
	}
	md->sha256.lengthHi += (md->sha256.curlen >> 29);
	md->sha256.lengthLo = n;
#endif /* HAVE_NATIVE_INT64 */	

/*
	append the '1' bit
 */
	md->sha256.buf[md->sha256.curlen++] = (unsigned char)0x80;

/*
	if the length is currently above 56 bytes we append zeros then compress.
	Then we can fall back to padding zeros and length encoding like normal.
 */
	if (md->sha256.curlen > 56) {
		while (md->sha256.curlen < 64) {
			md->sha256.buf[md->sha256.curlen++] = (unsigned char)0;
		}
		sha256_compress(md, md->sha256.buf);
		md->sha256.curlen = 0;
	}

/*
	pad upto 56 bytes of zeroes
 */
	while (md->sha256.curlen < 56) {
		md->sha256.buf[md->sha256.curlen++] = (unsigned char)0;
	}

/*
	store length
 */
#ifdef HAVE_NATIVE_INT64
	STORE64H(md->sha256.length, md->sha256.buf+56);
#else
	STORE32H(md->sha256.lengthHi, md->sha256.buf+56);
	STORE32H(md->sha256.lengthLo, md->sha256.buf+60);
#endif /* HAVE_NATIVE_INT64 */	
	sha256_compress(md, md->sha256.buf);

/*
	copy output
 */
	for (i = 0; i < 8; i++) {
		STORE32H(md->sha256.state[i], hash+(4*i));
	}
	memset(md, 0x0, sizeof(psDigestContext_t));
	return SHA256_HASH_SIZE;
}
#endif /* USE_SHA256 */
/******************************************************************************/
